Then my problem, when i run Log4om together with wsjt-x and JT-alert all works fine at first.
But recently the Log4om communicator got automatically switched off after logging a QSO.
I have to manually switch the communicator on again after each qso otherwise i got an error "not logged".
What could be the problem here?

If you see the red STOP button communicator is running. Looks like yo lost the
connections to the radio. Did you use Hamlib or Omnirig for CAT ?

If Omnirig start Log4OM first, then start WSJT-X and in the settings set the Radio to Omnirig
so you will have CAT for both programs.

How do you log to Log4OM ? Via JTalert ? Are the UDP in Communicator and in JTalert are
the same ? If not set both to the same UDP Port. You can find the used Port in the Communicator
in Settings/Inbound Settings. On my end it is 2236 and my Port settings in JTalert are 2236 too.

Thanks for your reply.
These are your answers to your questions:
1. I use OMNIRIG as CAT.
2. I start Log4OM First, then Wsjt-x and then JT-Alert.
3. I log via JT-Alert.

There is a strange thing happening. When i start, the info in de communicator for band and mode is correct.
After logging the first QSO, the communicator stops working and i have to switch it on again manually.
If i change band the info is not updated in the communicator screen.
If i change band, the band and mode info in Log4OM (top) is correct, the wsjt-x QRG is ok and also JT-Alert band info is ok.
If i manually switch the communicator on after a band switch (e.g. to 15 USB), the old info from the startposition is presented
(e.g. 30 USB) in communicator screen, but the new QSO info for a logged contact is correct in Log4OM.

I have checked all as you mentioned.
All running with administrator rights but no solution.
Guess i have to re-install all programs and try from bottom up.
Pitty because all works well xmt that the Log4OM communicator stops working after logging each QSO.